22621681 has 2 divisors, whose sum is σ = 22621682. Its totient is φ = 22621680.

The previous prime is 22621663. The next prime is 22621691. The reversal of 22621681 is 18612622.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21160000 + 1461681 = 4600^2 + 1209^2 .

It is a cyclic number.

It is not a de Polignac number, because 22621681 - 2⁷ = 22621553 is a prime.

It is a super-2 number, since 2×22621681² = 1023480902531522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (22621601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11310840 + 11310841.

It is an arithmetic number, because the mean of its divisors is an integer number (11310841).

Almost surely, 2^22621681 is an apocalyptic number.

It is an amenable number.

22621681 is a deficient number, since it is larger than the sum of its proper divisors (1).

22621681 is an equidigital number, since it uses as much as digits as its factorization.

22621681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 28.

The square root of 22621681 is about 4756.2254992799. The cubic root of 22621681 is about 282.8188104633.

The spelling of 22621681 in words is "twenty-two million, six hundred twenty-one thousand, six hundred eighty-one".